This invention generally relates to the field of electrical contactors and, more particularly, to a heat sink for dissipating heat generated by an electrical contactor connected to a mounting panel.
Contactor assemblies are used in electrical applications, such as aircraft power distribution systems, where power and current flow control of a multi-phase power distribution system is required. A contactor assembly typically has a panel on which several electrical contactors are mounted. Known mounting assemblies used to mount electrical contactors to the panels are constructed of thermally and electrically resistive materials, such as plastics or FR-4 for example.
Each of the contactors is connected to an electrical bus bar, and allows current to flow through the contactor and the corresponding bus bar whenever the contactor is in a closed position. The electrical power and current flow through the contactors is controlled by mechanically actuating a contact plate within the contactor such that, when current flow is desired to pass through the contactor, the contact plate is pushed into electrical contact with two leads and forms an electrical path coupling the leads, thereby allowing current to flow through it. Due to the amount of current traveling from the leads to the connector and the contact resistance at the contact points, waste heat is generated at the contact points and should be removed in order to prevent heat buildup. Additional factors such as imperfections in the contact surfaces or other imperfections can add to the amount of waste heat generated.
To dissipate the waste heat, previous known contactor mounting assemblies use thermally conductive electrical connections to allow the heat from the contact to be transmitted to the bus bars connected to each of the contactor's leads. The bus bars then dissipate heat into the atmosphere using natural convection and radiation techniques.